Transition between two solid‐solutions: Effective and easy way for fine Ce1−xGdxO2−x/2 powders preparation

Abstract Ceria, pure or doped, is an important electrolyte material in solid oxide fuel cells, catalysts, and plutonium surrogates. Even though ceria is a widely studied material, its coprecipitation with the most common doping element, gadolinium, remains mostly overlooked. Here, we present a comprehensive study of gadolinium–cerium oxalates prepared by coprecipitation of gadolinium (III) and cerium (III) salts by oxalic acid under different reaction conditions and element ratios. For this purpose, we assessed the effects of basic precipitation conditions on the final oxalate size, shape, and conversion into the corresponding oxides. The results showed that coprecipitation with oxalic acid yields and ideal solid solution, which translates into the oxides. This low‐cost and straightforward synthetic route provides then high‐quality solid solutions of Ge–Gd in the oxide lattice. Thus, this approach has a high industrialization potential, with significant advantages over hydrolysis or hydrothermal techniques.